Several years ago, my friend adopted Mimi, an 18 month old girl from China. Not long after, I came to visit her and noticed that Mimi was making a gesture for more food. My friend and I are both speech pathologists, and I recognized that she had taught Mimi sign language - and it was working. She was 18 months old and did not understand or speak English, but she was able to communicate with her English-speaking mother using sign language.
It was interesting to me when I read this article on The Science of Gestures. I always emphasize the use of gestures with my clients for a number of reasons. Gestures serve to:

make the presenter look confident.

channel nervous energy.

emphasize certain words or points, making the speaker more dynamic.

reduce monotone, enabling speakers to vary intonation.

But I wasn't aware of the neuroscience behind gesturing. In two separate studies with children, researchers found that using and watching gestures helped students retain more information.

Most speakers are both visual and auditory presenters. That means they use the spoken word and they project PowerPoint slides. The audience sees and hears the message but the missing link is kinesthetic learning. And that's where gestures come in.

Effective public speakers anchor their message with gestures. I once attended a presentation where the speaker told the audience, "Touch your mind and your heart," to help the them remember his point.

We all know someone who speaks with their hands. I remember one man who gesticulated wildly whenever he spoke. This irritated his wife to no end. One day in frustration, she grabbed his hands as he was speaking. He stopped the conversation, looked at her and pleaded, "Let me talk!" It seemed hand movements were a way for him to communicate.

It turns out that using gestures help us to clear our cache, or short-term memory, when we are speaking. Moving our hands in conversation and while presenting, allows us to process more information-like Mimi who learned sign language at 18 months. But gestures are not just for children. They have a lot of value for adult public speakers, as well.

Not sure what to do with your hands? Watch this youtube video and find out.